Gasoline composition

ABSTRACT

Improved hydrocarbon fuel compositions suitable for employment in internal combustion engines, e.g., spark-ignition engines, compression-ignition engines, and turbine engines, and the operation of said internal combustion engines therewith. The hydrocarbon fuel compositions of the instant invention comprise a major proportion of a hydrocarbon fuel, especially one boiling in the gasoline boiling range, and a minor proportion of an additive which imparts to the hydrocarbon fuel composition detergent, anti-icing, and anti-corrosion properties. The additives are hydrocarbon fuel-soluble organic compounds containing at least two amide linkages.

United States Patent Jameson [451 Apr. 11, 1972 [54] GASOLINE COMPOSITION 3,444,170 5/1969 Norman et al. ..2s2/s1.5 A [72] Inventor: Ernest J. Jamieson, Highland Park, NJ. [73] Assignee: Cities Service Oil Company, Tulsa, Okla. 3,233,}; 3/ I( iotltshlall et al 252 51 [22] Filed: May 29, 1969 0e sc .5 A

. Primary Examiner-Daniel E. Wyman [2]] App]. No" 829,143 Assistant Examiner-W. J. Shine AttorneyJ. Richard Geaman [52] US. Cl ..44/66, 44/63, 44/71,

44/DIG. 1, 252/392, 260/404.5 57 ABSTRACT [51] Int. Cl ..Cl0l1/18,Cl0ll/22 581 Field of Search 244/56 D, 63, 66, 71; 252/392, P y q hydmcafbm '9 PP Sm'able f Fi P 252/855 E; 260/4045 ment in internal comb u st1on engines, e.g., spark-ignition en- 7, V W V V gines, compression-ignition engines, and turbine engines, and the operation of said internal combustion engines therewith. [56] References Cited The hydrocarbon fuel compositions of the instant invention UNITED STATES PATENTS comprise a major proportion of a hydrocarbon fuel, especially one boiling in the gasoline boiling range, and a minor propor- 2,7l8,503 9/1955 ROCChlm ..44/66 X tion of an additive hi imparts to the hydrocarbon fuel 2,843,464 7/ 1958 aim "44/66 composition detergent, anti-icing, and anti-corrosion proper- 3,169,980 I965 Benoit 252/51-5 A ties. The additives are hydrocarbon fuel-soluble organic com- 3,296,133 l/ l 967 Ratner et al. .....44/58 X pounds containing at least two amide linkages. 3,310,492 3/1967 Benoit 252/515 A 3,337,459 8/1967 Ford ..44/58 X 13 Claims, No Drawings BACKGROUND OF THE INVENTION Under certain driving conditions, such as when ambient The foregoing objects are accomplished in incorporating into a major proportion of a hydrocarbon fuel, especially one boiling in the gasoline boiling range, i. e., about 50 F. to about 450 F., a minor proportion of an additive which is a hydrocartemperamre is just Slightly above the f i point and there 5 bon fuel-soluble organic compound containing at least two is a high relative humidity, carburetor icing may occur. This is a result of evaporation of the fuel as it is injected into the carburetor. As the fuel vaporizes and mixes with air, the temperature drop as a result of evaporation causes moisture in the air to freeze on the throttle plate, resulting in engine stalling.

Another cause of engine stalling and rough idling is the build-up of deposits in the throttle body section of the carburetor. This build-up of deposits in the induction systems of engines is especially favored by engine operating conditions that involve considerable idling. The rough idling and engine stalling resulting from such accumulation of deposits has required frequent carburetor adjustments and reconditioning in order to obtain satisfactory engine operation.

The principle point for build-up of these deposits is adjacent to the throttle plate, the position of which controls the ratio of fuel to air. As the deposits accumulate, the flow of air while the engine is idling is hindered with no corresponding change in the flow of fuel. The resultant fuel-air mixture is thus rich in fuel, causing the engine to idle erratically and to stall. In order to adjust for the presence of these deposits, the idle speed may be increased. This causes the throttle to open slightly, thereby allowing more air to flow, while at the same time supplying more fuel. An adjustment must therefore be made to reduce the flow of fuel by a compensating amount.

In addition, deposits often accumulate in the air passage. The resultant restriction causes the manifold vacuum to increase, thereby drawing more fuel into the engine to again give a rich fuel-air mixture which causes rough idling and engine stalling.

It appears that the main source of deposits in the induction system of an engine is contaminants in the intake air, particularly when the engine is operating at idle. Engine blowby is the principle source of these contaminants. Other sources are dust and exhaust from other vehicles.

SUMMARY It is now possible to avoid frequent mechanical adjustments and engine reconditioning made necessary by the build-up of deposits in the induction system, particularly in the carburetor. A fuel composition has been discovered which is capable not only of preventing the build-up of these deposits but which will also reduce already existing deposits. In addition, this fuel composition has anti-icing properties. Thus the tendency for ice to form on the throttle plate is reduced, thereby eliminating engine stalling due to carburetor icing. The fuel composition of the instant invention, in addition to detergent and antiicing properties, functions as an anti-corrosion agent as well.

It is therefore an object of this invention to provide a hydrocarbon fuel composition, especially one boiling within the gasoline boiling range, which has detergent properties whereby the accumulation of deposits in the induction system of an engine is prevented and already present deposits are reduced.

It is another object of this invention to provide a hydrocarbon fuel composition, especially one boiling within the gasoline boiling range, which has anti-icing and anti-corrosion properties.

It is yet another object of this invention to operate an internal combustion engine, specially a spark-ignition engine, with a hydrocarbon fuel composition, especially one boiling within the gasoline boiling range, having detergent properties as well as anti-icing and anti-corrosion properties.

It is still another object of this invention to prepare novel compositions of matter which when incorporated into a hydrocarbon fuel impart desirable properties thereto, said compositions of matter being prepared by condensing a dimerized or trimerized polyunsaturated monocarboxylic fatty acid with an amine to form the corresponding diamide or triamide.

Other objects of this invention will be apparent from the description which follows.

amide linkages,

The additives most useful in the present invention have the following general structures:

wherein R is hydrogen or a hydrocarbyl group of about one to about 30 carbons and preferably about five to about 25 carbons, e.g., an alkyl group, an aryl group, an aralkyl group, an alkaryl group, a cycloparaffin group, a cycloolefin group, or an aliphatic olefin group; R R and R, are polyvalent hydrocarbyl groups of about two to about 65 carbons and preferably about three to about 55 carbons, e.g., polyvalent aryl groups or olefinically saturated or unsaturated polyvalent alkyl groups, aralkyl groups, alkaryl groups, and naphthene groups; it is equal to or greater than I; and y is such that the total number of amide linkages in the molecule is two or more. One or more hydrogens on hydrocarbyl groups R R R and R may be replaced by a heterocyclic group such as an imidazolyl group or by a functional group such as halide, hydroxyl, carboxyl, carbonyl, ester, mercaptyl, amino, substituted amino, or amide. R R R and R 4 may be the same or different whenever they occur more than once in any one molecule. R and R may be the same or different in compounds represented by structure II. When x is greater than 1 in compounds represented by structure III, the portion of the molecule within brackets may be attached to the same or different carbons in R Polyamides of the type represented by structure I may be prepared, for example, by condensing amino acids with one another through their respective amino and carboxyl groups, Polyamides of the type represented by structure Il may be prepared, for example, by condensing dicarboxylic acids with diamines.

Particularly useful in the practice of this invention are amides of the type represented by structure III when x is one. These diamides may be prepared by condensing a dicarboxylic acid with ammonia or an amine. Generally, the dicarboxylic acids contain about three to about 50 carbons. Examples of suitable dicarboxylic acids are malonic, succinic, glutaric, adipic, azeleic, terephthalic, and dimer acids produced by the dimerization of polyunsaturated monocarboxylic fatty acids of about 16 to about 20 carbons. Dicarboxylic acids containing between about 30 and about 40 carbons, especially the aforementioned dimer acids, are preferred. In addition to ammonia the dicarboxylic acids may be condensed with amines selected from primary and secondary amines as well as compounds containing two or more amino groups. Examples of suitable amines are methylamine, diethylamine, n-propy n-hex' ylamine, cyclohexylamine, stearylamine, aniline,

ethanolamine, pyrrolidines, 2-chlorononylamine, 3-mercaptobutylamine, ethylenediamine, diethylenetriamine, and N- methylaniline.

Another class of amines that finds use in the practice of this invention is aminoalkyl substituted imidazolines of the general structure:

esi

wherein x is l to 8 and R is a hydrocarbyl group. When this class of amine is condensed with, for example, a dicarboxylic acid, the following type of diamide is produced:

wherein X represents the non-carboxyl portion of the dicarboxylic acid.

The preferred amines for formation of the amides of this invention are lO-phenylstearylamine, N-stearyl 1, 3 propylenediamine, and N-( l0-phenylstearyl)-l, 3 propylenediamine.

An especially useful dicarboxylic acid is a commercial dimer acid produced by Emery Industries, Inc. under the trade name of Empol 1014. This dimer acid is produced by the dimerization of a polyunsaturated C monocarboxylic fatty acid to produce a C aliphatic dicarboxylic acid. The exact structure of this dimer acid is not known with certainty, but it appears to be a long chain dicarboxylic acid with two or more alkyl side chains and containing at least one ethylenic bond. The molecule may possibly contain a cyclic structure. Some physical properties of this dimer acid are refractive index at 25 C., 1.4706; specific gravity at 25/20 C., 0.95; and viscosity at 25 C., 5,100 centistokes.

While Empol 1014 may be condensed with ammonia or primary or secondary amines to form the corresponding diamides, it has been found that a particularly satisfactory class of amines is derived from 1, 3 propylenediamine. Of these, N- (IO-phenylstearyl) l, 3 propylenediamine is especially efficacious when condensed with the dimer acid. The product may have the IO-phenylstearyl group on either the amide nitrogen or the amine nitrogen, and both isomers are probably formed:

In addition to the dicarboxylic acids used to form amides represented by structure III when x is l, acids containing three, four or more carboxyl groups may be converted to amides and used successfully in the practice of this invention. An example is a trimer acid designated as Empol 1040 which comprises about 91 percent of the trimer of a polyunsaturated C monocarboxylic fatty acid, being a C tricarboxylic acid.

In addition to forming a polyamide by condensing a specific amine with a specific polycarboxylic acid, it is possible to condense mixtures of amines with mixtures of acids. An example of a useful mixture of acids is Empol 1022 which is comprised of about three parts of the dimer and about one part of the trimer of a polyunsaturated C monocarboxylic fatty acid. An example of a suitable mixture of amines is two parts of 10- phenylstearylamine and one part of N IO-phenylstearyl) 1, 3 propylenediamine.

The polyamides of this invention may be prepared by adding one mole of the amine to each equivalent of the acid in a suitable solvent and heating the mixture. Water formed as a by-product of the condensation reaction is removed from the reaction mixture, for example by azeotropic distillation. It is convenient when using an aromatic solvent such as toluene or xylene to employ a water separator to collect the by-product water. On completion of the reaction, removal of the solvent as, for example, by distillation leaves the polyamide.

The quantity of the polyamide additive of this invention which is incorporated into the hydrocarbon fuel will vary from case to case depending on the type of fuel and the specific additive used as wellas the properties desired in the fuel. Generally, about 1 to about 25 pounds of additive per thousand barrels of hydrocarbon fuel composition (PTB) are used. The preferred range of additive is about 5 to about 15 PTB.

In addition to the additives of the instant invention, other conventional additives may be incorporated into the hydrocarbon fuel. Thus conventional additives may be added, for example, water dispersants to improve the water tolerance of the fuel composition, organo lead compounds such as tetraethyl lead to increase the octane rating of the fuel composition, and conventional additives to further enhance the anti-icing properties of the hydrocarbon fuel composition.

DESCRIPTION The following specific examples are presented in order to more fully illustrate the preparation and the unique properties of representative additives of this invention.

EXAMPLE I To a stirred solution of 25.4 g. (0.090 equiv., 0.045 mole)of Empol 1014 dimer acid in 150 ml. of toluene were added 39.9 g. (0.099 mole) of N (lO-phenylstearyl) l, 3 propylenediamine. An exotherm resulting from the addition of the diamine caused the temperature of the reaction mixture to increase from room temperature to 40 C. The reaction mixture was heated under reflux for 1% hours at a temperature of about C. and the water formed as a by-product of the condensation reaction was removed by azeotropic distillation and collected in a Dean-Stark trap. Refluxing was continued for an additional 1% hours. Total water collected in the Dean- Stark trap during the 2% hour reaction time was 1.5 ml. while the theoretical amount was 1.6 ml. The toluene was removed by distillation to yield a residue of the diamide which was a gasoline-soluble dark yellow viscous liquid. Infrared analysis showed a strong amide absorption band at 1,650 cm The results of elemental analysis and a molecular weight determination of the diamide are shown in Table l and are seen to agree closely with the corresponding theoretical values. The product was designated Amide I.

TABLE I Theoretical Found Molecular Weight 1334 I229 91: C 81.0 81.38 I H 12.4 12.29 9t 2.4 2.42 'i N 4.2 4.00 7: Basic N 2.1 2.30

EXAMPLE II To a stirred suspension of 23.6 g. (0.4 equiv.) of succinic acid in 50 g. of toluene was added a solution of 160.8 g. (0.4 mole) of N (IO-phenylstearyl) 1, 3 propylenediamine in 50 g. of toluene. The mixture was stirred under reflux (135 C.) for 14 hours. The water formed as a by-product of the condensation reaction was removed by azeotropic distillation and collected in a Dean-Stark trap. The theoretical amount of water for formation of the diamide was 7.2 ml. The amount of water formed as a result of the condensation reaction was 9.97 ml. The excess water can be explained as due to some cyclization to form a substituted tetrahydropyrimidine. The toluene was then removed by distillation to yield the diamide. Analysis showed the product to contain 3.54 percent basic nitrogen; the theoretical amount is 3.16 percent basic nitrogen. The product was designated Amide II.

EXAMPLE III To a stirred suspension of 29.2 g. (0.4 equiv.) of adipic acid in 50 g. of toluene was added a solution of 160.8 g. (0.4 mole) of N IO-phenylstearyl) 1, 3 propylenediamine in 50 g. of toluene at the rate of about 1 ml. per minute. The mixture was stirred under relfux (132 C.) for 17 hours and by-product water removed by azeotropic distillation. The theoretical amount of water for diamide formation was 7.2 ml.; 8.7 ml. of water were produced. The toluene was removed by distillation yield the diamide. Analysis showed the diamide to contain 3.60 percent basic nitrogen; the theoretical amount is 3.10 percent basic nitrogen. The product was designated as Amide lll.

EXAMPLE IV In this experiment the acid was Empol 1022 which is comprised of about three parts dimer and about one part trimer of a polyunsaturated monocarboxylic C fatty acid. To a stirred solution of 70.58 g. (0.25 equiv.) of Empol 1022 in 50 g. of toluene was added a solution of 100.5 g. (0.25 mole) ofN (10-phenylstearyl) 1, 3 propylenediamine in 100 g. of toluene at the rate of about 1 ml. per minute. The mixture was stirred under reflux (126 C.) for 17 hours and by-product water removed by azeotropic distillation. The theoretical amount of water for polyamide formation was 4.5 ml.; 4.75 ml. of water were produced in the condensation reaction. The polyamide was recovered from the toluene as before. The polyamide on analysis was found to contain 2.39 percent basic nitrogen; the theoretical amount is 2.10 percent basic nitrogen. The product was designated Amide IV.

EXAMPLE V The acid used in this example was Empol 1040 which is comprised of about 91 percent trimer and about dimer of a polyunsaturated monocarboxylic C fatty acid. To a stirred solution of 70.5 g. (0.25 equiv.) of Empol 1040 in 75 g. of toluene was added a solution of 100.5 g. (0.25 mole) of N phenylstearyl) 1, 3 propylenediamine in 75 g. of toluene. The mixture was stirred under reflux 120 C.) for 23 hours and by-product water removed by azeotropic distillation. The theoretical amount of water for polyamide formation was 4.50 ml.; 5.22 ml. of water were collected as byproduct of the condensation reaction. The polyamide was recovered from the toluene as previously described. Analysis showed the polyamide to contain 2.50 percent basic nitrogen; the theoretical amount is 2.10 percent. The product was designated Amide V.

EXAMPLE VI To a stirred solution of 68.0 g. (0.24 equiv.) of Empol 1,014 dimer acid in 60 g. of toluene was added a solution of 83.0 g. (0.24 mole) of 10 phenylstearylamine in 101 g. of toluene. The mixture was stirred under reflux and by-product water removed by azeotropic distillation. The reflux temperature was 119 C. for the first 8% hours. Then ml. of toluene was removed by distillation, thereby causing the reflux temperature to increase to 134 C. The reaction mixture was refluxed at 134 C. for 5 hours. Additional toluene was then removed to increase the reflux temperature to 167 C. and the mixture was refluxed at this temperature for 9 hours. The theoretical amount of water for diamide formation was 4.3 ml.; 3.3 ml. of water were collected. The diamide was recovered from the toluene as previously described. Elemental analysis showed the diamide to have a total nitrogen'content of 2.02 percent; the theoretical amount is 2.23 percent. The product was designated Amide VI.

EXAMPLE VII recovered from the toluene as previously described; it was designated Amide Vll.

EXAMPLE VIII In this example a diamide was prepared by condensing dimer acid Empol 1014 with a 1 (B aminoethyl) 2 alkyl 2 imidazoline in which the alkyl group in the 2 position was a mixture of heptadecenyl and heptadecadienyl groups. In m1. of xylene at room temperature were placed 0.4 equiv. of dimer acid Empol 1014 and 0.4 mole of the 1 (B aminoethyl) 2 alkyl 2 imidazoline. The reaction mixture was heated under reflux at 150-160 F. for about 16 hours. The water formed as a byproduct of the condensation reaction was removed by azeotropic distillation and collected in a Dean-Stark trap. The theoretical amount of water for diamide formation was 7.2 ml.; the quantity of water collected was 7.0 ml. The xylene was removed by distillation under reduced pressure (about F. at 5-10 mm. Hg). The product, a dark brown viscous liquid, was designated Amide VIII.

EXAMPLE IX Using the procedure described in Example VIII, 0.4 equiv. of azeleic acid was condensed with 0.4 mole of 1 (B aminoethyl) 2 heptadecyl 2 imidazoline to form the diamide. The water formed as a by-product of the condensation reaction was 7.2 ml.; 100 percent of the theoretical amount for diamide production. The product, a light brown waxy solid, was designated Amide IX.

EXAMPLE X When Example VIII is repeated using 0.4 equiv. of trimer acid Empol 1040 and 0.4 mole of n-dodecylamine, the corresponding triamide, designated Amide X,is obtained.

EXAMPLE XI When Example VIII is repeated using 0.4 equiv. of dimer acid Empol 1014 and 0.4 mole of N-Stearyl 1, 3 propylenediamine, the corresponding diamide, designated Amide X1, is obtained.

7 EXAMPLE XII The efficacy of various amides of this invention as carburetor detergents was determined. The procedure used to determine this property was as follows:

Engine blow-by contaminants were generated in an engine and collected in a flask. At the end of the collection period the water phase was separated from the fuel phase, the later being discarded. The water phase of the contaminants was used for the carburetor detergency evaluations.

The carburetor detergency test is run on a Cooperative Lubricants Research (CLR) engine, a single cylinder research engine manufactured by Laboratory Equipment Company. The contaminants are injected into the throttle body of a CLR engine running with a rich mixture and on which the throttle plate has been replaced by a 200 mesh stainless steel screen. The amount of deposits accumulated on the screen after three hours of engine operation indicates the detergency performance of the fuel. Experimental fuels, with reference and base fuel runs, are tested with the same batch of contaminants.

At the conclusion of the "three hour run, the 200 mesh screen is removed and evaluated for contaminant accumulation. The reflectance of the screen, determined by means of a reflectance meter, is a measure of the amount of deposits accumulated on the screen. The higher the reflectance, the cleaner the screen, i.e., the lower the accumulation of deposits.

The effectiveness of an additive is represented as the ratio, expressed as a percentage, of the average screen reflectance for the fuel containing the additive to the average screen reflectance for a base fuel containing no detergency additive. Thus an experimental additive that equaled the performance of the base fuel would have an effectiveness of 100 percent, an experimental additive that performed at one half the level of the base fuel would have an effectiveness of 50 percent, and an experimental additive that performed at twice the level of the base fuel would have an effectiveness of 200 percent.

The carburetor detergency effectiveness of a number of the amides of this invention was determined by the above procedure and the results are reported in Table II. The additives were dissolved in gasoline in the concentrations shown in the table. A premium base gasoline containing 3 ml. of tetraethyl lead per gallon was used. In addition, the gasoline contained conventional additives, e.g., a halogenated hydrocarbon scavenger, a metal deactivator such as a salicylidine diamine, and a phenolic anti-oxidant. Some of the experimental gasoline compositions also contained a water dispersant additive sold by Tretolite Company under the name DS-4l5. This additive is an aromatic solvent solution of an oxyalkylated phenolic resin, an acylated alkanolamine, and an arylsulfonate. Several runs were made for each gasoline composition and the reflectance value shown is an average of the values obtained in the series of runs.

The foregoing data illustrate the higher reflectance values obtained from gasoline compositions containing the additives of this invention relative to the reflectance obtained from a base fuel containing no carburetor detergency additive. It was also found that amides of this invention compared favorably with commercially available carburetor detergency additives. The experimental amides shown in Table II were found to be 5.6 percent to 83.3 percent more effective as carburetor detergents than was a commercially available carburetor detergent EXAMPLE XIII When Example XII is repeated using 1 PTB of Amide VIII and no water dispersant and using 15 PTB of Amide III and no water dispersant, comparable results are obtained.

EXAMPLE XIV When Example XII is repeated using an unleaded gasoline containing metal deactivator and anti-oxidant but no scavenger and containing (a) 6 PTB of Amide I and no water dispersant and containing (b) 25 PTB of Amide IV plus 0.25 PTB of water dispersant, comparable results are obtained.

EXAMPLE XV The efficacy of various amides of this invention as anti-icing additives was determined. The procedure used was as follows:

The test is run on a CLR single engine coupled to a speed controlled dynamometer. The engine is fitted with a special, thermally isolated carburetor with external float bowls; no idle fuel system is used. The carburetor has an adjustable main jet and the throttle body is constructed of glass or clear plastic so icing can be confirmed by visual inspection. A temperature and humidity control system supplies inlet air to the carburetor at the desired conditions and also to a glass or clear plastic box enclosing the carburetor.

All anti-icing additives are evaluated in a blended base fuel composed of 25 volume percent of ASTM isooctane and 75 volume percent of precipitation naphtha and containing 1.5 ml. /gallon of tetraethyl lead. Also present are a scavenger, metal deactivator, and an anti-oxidant. A non-icing purge fuel consisting of the base fuel containing 5.5 percent of isopropyl alcohol is used in the test. The anti-icing properties of gasoline compositions containing amides of this invention are compared to those of the base fuel containing no anti-icing additive.

Ice formation on the throttle plate of the carburetor is measured by an increase of manifold vacuum caused by a choking of the engine by the ice formation. The time in seconds for the manifold vacuum to increase 1.5 and 2.0 inches of mercury are recorded as time to ice with the fuel which is being evaluated. An increase in manifold vacuum of 1.5 inches of mercury is defined as trace ice and an increase in manifold vacuum of 2.0 inches of mercury is defined as severe ice.

Engine operating conditions are set so as to cause a reference fuel, i.e., a base fuel containing a reference antiicing additive, to ice sufficiently to cause a 2.0 inch manifold vacuum increase in 40 to 50 seconds. When these conditions are set, the base fuel containing no anti-icing additive will ice to the same extent in 18 to 20 seconds. Once these operating conditions have been achieved, the anti-icing characteristics of base fuel containing the experimental additives can be evaluated.

In running the test on a fuel composition containing an experimental additive, once ice severe enough to rain the manifold vacuum 2.0 inches of mercury has formed, the carburetor is switched to the purge fuel which removes the ice. After 50 seconds to allow for ice removal and engine stabilization, the carburetor is switched back to the experimental fuel. The above procedure is repeated until five runs on the experimental fuel have been made, the times for manifold vacuum increases of 1.5 and 2.0 inches of mercury being noted. The times of the five runs are then averaged for each manifold TABLE III Concen- Effectiveness,

tration, Average seconds percent of time Additive PTB to Ice for base fuel Manifold vacuum 1.5 in., 2.0 in 1.5 in., 2.0 in.

increase, in. Hg. None (Base Fuel) 17.0 sec., 18.4 sec. 100%, 100%. Amide VII. 12. 8 20.4 sec., 27.2 sec. 120.0%, 147. 89. Amide II 12. 8 20.4 sec., 24.0 sec 120.0%, 130 5 Amide III. 8 20.2 sec., 26.6 sec. 118.8%, 144

Amide I .I

The data in Table III show that the amides of this invention considerably improve the anti-icing properties of a base fuel when added thereto.

EXAMPLE XVI When Example XV is repeated using (a) PTB of Amide X plus 0.25 PTB water dispersant and using (b) PTB of Amide IV and no water dispersant, comparable results are obtained.

EXAMPLE XVII When Example XV is repeated using an unleaded gasoline containing metal deactivator and anti-oxidant but no scavenger and containing (a) PTB of Amide l plus 0.25 PTB of water dispersant and containing (b) 8 PTB of Amide XI and no water dispersant, comparable results are obtained.

EXAMPLE XVIII The corrosion inhibition characteristics of fuels containing the polyamides of this invention were determined by means of the Modified ASTM D 665-54 Rust Test. The procedure, in brief, is to immerse steel spindles in an agitated mixture of the test fuel and synthetic sea water heated to 100 F. for 20 hours. At the end of the run the spindle is removed and the percent rust determined by visual inspection. A rating of No Rust is given if there is no rust on the spindle, while a rating of 100 percent Rust is given if the entire surface of the spindle is covered with rust. Thus the percent rust is the percent of the surface of the spindle that is covered with rust.

The efficacy of Amide I as a corrosion inhibitor in a gasoline composition was determined. The base gasoline contained tetraethyl lead as well as the usual scavengers, metal deactivators, and antioxidants. Amide I and water dispersant DS-415 were dissolved in the base gasoline composition in the amounts shown in Table IV. The percent rust was determined for each composition by the procedure outlined above. A blank, i.e., base gasoline containing no corrosion inhibitor, was run for comparative purposes. Duplicate determinations were made;the values reported in the table for percent Rust are the averages of the duplicate determinations.

Amide I 12.8

l2.5 DS-4l5 0.5

The above data show the corrosion resistance imparted to a gasoline composition by an amide of this invention relative to a base gasoline composition not containing a corrosion inhibitor.

EXAMPLE XIX When Example XVIII is repeated using (a) 23 PTB of Amide IV plus 0.5 PTB of water dispersant and using (b) 2 PTB of Amide V with no water dispersant, comparable results are obtained.

EXAMPLE xx When Example XVIII is repeated using an unleaded gasoline containing metal deactivator and antioxidant but no scavenger and containing (a) 17 PTB of Amide II plus 0.25 PTB of water dispersant and containing (b) 3 PTB of Amide VI but no water dispersant, comparable results are obtained.

It will be understood that various changes in details described and illustrated herein in order to explain the invention may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims.

Iclaim:

1. A gasoline composition comprising a major proportion of a liquid hydrocarbon boiling in the gasoline boiling range and about 1 to about 25 pounds per thousand barrels of said composition of a gasoline soluble polyamide which is the condensation product of 1 mole of a polyamine with each equivalent of a polycarboxylic acid.

2. The composition of claim 1 wherein the gasoline soluble polyamide is the condensation product of 2 moles of N (l0- phenylstearyl) l, 3 propylenediamine and 1 mole of a dimerized polyunsaturated monocarboxylic fatty acid of 18 carbons.

3. The composition of claim 1 wherein the gasoline soluble polyamide is the condensation product of 2 moles of N (l0- phenylstearyl) l, 3 propylenediamine and 1 mole of succinic acid.

4. The composition of claim 1 wherein the gasoline soluble polyamide is the condensation product of 2 moles of N l0- phenylstearyl) l, 3 propylenediamine and 1 mole of adipic acid.

5. The composition of claim 1 wherein the gasoline soluble polyamide is the condensation product of 2 moles of N l0- phenylstearyl) l, 3 propylenediamine and 1 mole of malonic acid.

6. The composition of claim 1 wherein the gasoline soluble polyamide is the condensation product of 3 moles of N l0- phenylstearyl) l, 3 propylenediamine and l mole of a trimerized polyunsaturated monocarboxylic fatty acid of 18 carbons.

7. A gasoline composition comprising a major proportion of a liquid hydrocarbon boiling in the gasoline boiling range and about 1 to about 25 pounds per thousand barrels of said composition of a gasoline soluble polyamide which is the condensation product of 2 moles of lO-phenylstearylamine and 1 mole of a dimerized polyunsaturated monocarboxylic fatty acid of 18 carbons.

8. The composition of claim 2 wherein the gasoline soluble polyamide is present in an amount from about 5 to about 15 pounds per thousand barrels of the composition.

9. An additive which when incorporated into gasoline imparts thereto anti-icing, anti-corrosion, and carburetor detergency properties comprising the gasoline soluble polyamide obtained by condensing 2 moles of N (IO-phenylstearyl) l, 3 propylenediamine with 1 mole of a dimerized polyunsaturated monocarboxylic fatty acid of 18 carbons.

10. A compound which when incorporated into gasoline imparts thereto anti-icing, anti-corrosion and carburetor detergency properties comprising the gasoline soluble polyamide obtained by condensing 2 moles of IO-phenylstearylamine with 1 mole of a dimerized polyunsaturated monocarboxylic fatty acid of 18 carbons.

11. An additive which when incorporated into gasoline imparts thereto anti-icing, anti-corrosion, and carburetor detergency properties comprising the gasoline soluble polyamide obtained by condensing 3 moles of N l phenylstearyl) l, 3 propylenediamine with 1 mole of a trimerized polyunsaturated monocarboxylic fatty acid of 18 carbons.

12. In the method of operating a spark ignition engine wherein a gasoline fuel is passed through a fuel supply system into a combustion chamber of said engine and said gasoline fuel is caused to ignite therein, the improvement comprising operating said engine on a gasoline fuel containing about 1 to about 25 pounds per thousand barrels of said fuel of a gasoline soluble polyamide which is the condensation product of 1 mole of an amine with each equivalent of a polycarboxylic acid wherein the amine is selected from the group consisting of monoamines containing about 24 to 30 carbons and polyamines.

13. The method of claim 12 wherein the gasoline soluble polyamide is the condensation product of 2 moles of N (l0- phenylstearyl) l, 3 propylenediamine and 1 mole of a dimerized polyunsaturated monocarboxylic acid of 18 carbons. 

2. The composition of claim 1 wherein the gasoline soluble polyamide is the condensation product of 2 moles of N - (10-phenylstearyl) - 1, 3 - propylenediamine and 1 mole of a dimerized polyunsaturated monocarboxylic fatty acid of 18 carbons.
 3. The composition of claim 1 wherein the gasoline soluble polyamide is the condensation product of 2 moles of N - (10-phenylstearyl) - 1, 3 - propylenediamine and 1 mole of succinic acid.
 4. The composition of claim 1 wherein the gasoline soluble polyamide is the condensation product of 2 moles of N - (10-phenylstearyl) - 1, 3 - propylenediamine and 1 mole of adipic acid.
 5. The composition of claim 1 wherein the gasoline soluble polyamide is the condensation product of 2 moles of N - (10-phenylstearyl) - 1, 3 - propylenediamine and 1 mole of malonic acid.
 6. The composition of claim 1 wherein the gasoline soluble polyamide is the condensation product of 3 moles of N - (10-phenylstearyl) - 1, 3 - propylenediamine and 1 mole of a trimerized polyunsaturated monocarboxylic fatty acid of 18 carbons.
 7. A gasoline composition comprising a major proportion of a liquid hydrocarbon boiling in the gasoline boiling range and about 1 to about 25 pounds per thousand barrels of said composition of a gasoline soluble polyamide which is the condensation product of 2 moles of 10-phenylstearylamine and 1 mole of a dimerized polyunsaturated monocarboxylic fatty acid of 18 carbons.
 8. The composition of claim 2 wherein the gasoline soluble polyamide is present in an amount from about 5 to about 15 pounds per thousand barrels of the composition.
 9. An additive which when incorporated into gasoline imparts thereto anti-icing, anti-corrosion, and carburetor detergency properties comprising the gasoline soluble polyamide obtained by condensing 2 moles of N - (10-phenylstearyl) - 1, 3 -propylenediamine with 1 mole of a dimerized polyunsaturated monocarboxylic fatty acid of 18 carbons.
 10. A compound which when incorporated into gasoline imparts thereto anti-icing, anti-corrosion and carburetor detergency properties comprising the gasoline soluble polyamide obtained by condensing 2 moles of 10-phenylstearylamine with 1 mole of a dimerized polyunsaturated monocarboxylic fatty acid of 18 carbons.
 11. An additive which when incorporated into gasoline imparts thereto anti-icing, anti-corrosion, and carburetor detergency properties comprising the gasoline soluble polyamide obtained by condensing 3 moles of N - (10 - phenylstearyl) - 1, 3 -propylenediamine with 1 mole of a trimerized polyunsaturated monocarboxylic fatty acid of 18 carbons.
 12. In the method of operating a spark ignition engine wherein a gasoline fuel is passed through a fuel supply system into a combustion chamber of said engine and said gasoline fuel is caused to ignite therein, the improvement comprising operating said engine on a gasoline fuel containing about 1 to about 25 pounds per thousand barrels of said fuel of a gasoline soluble polyamide which is the condensation product of 1 mole of an amine with each equivalent of a polycarboxylic acid wherein the amine is selected from the group consisting of monoamines containing about 24 to 30 carbons and polyamines.
 13. The method of claim 12 wherein the gasoline soluble polyamide is the condensation product of 2 moles of N - (10-phenylstearyl) - 1, 3 - propylenediamine and 1 mole of a dimerized polyunsaturated monocaRboxylic acid of 18 carbons. 